With the game finely poised after two quickfire first-half goals, Swansea took a shock lead just after the hour mark.
Nacho Monreal took a quick throw-in down the left and Laurent Koscielny was immediately put under pressure.
The Frenchman opted to find his goalkeeper, only for the usually reliable Petr Cech to miss his kick and present Jordan Ayew with a tap-in.
It was an uncharacteristic error from Cech, but Swansea certainly weren't complaining.
Check out the goal for yourself below:
30 January 2018